Negative pressure wound therapy for treatment of periodontal disease

ABSTRACT

Disclosed are devices, systems and methods for treating periodontal disease and/or other oral wounds using particularized oral appliances and associated negative pressure systems. The various oral appliances include one or a plurality of surfaces for engagement with various anatomical structures within the oral cavity, where the engagement can include sealing engagement with soft tissue (gingival) surfaces of the upper and/or lower dental arches. Additional features disclosed can further promote healing of regions affected by periodontal pocket formation.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/442,610 entitled “Negative Pressure Wound Therapy for Treatment ofPeriodontal Disease,” filed Feb. 24, 2017, which in turn claims thebenefit of PCT Patent Application Serial Number PCT/US16/56291 entitled“Negative Pressure Wound Therapy (NWPT) for Treatment of PeriodontalDisease,” filed Oct. 10, 2016, which in turn claims priority to U.S.Provisional Patent Application Ser. No. 62/240,313 entitled “NegativePressure Wound Therapy (NWPT) for Treatment of Periodontal Disease,”filed Oct. 12, 2015. Each of these disclosures are incorporated byreference herein in their entireties.

TECHNICAL FIELD

This invention relates generally to systems, devices and methods forapplying suction and/or continuous or intermittent negative pressure tothe oral cavity of a patient for treating conditions affecting softtissue structures within the mouth, but most commonly those involvingthe soft tissues at the base of the teeth (gums/gingival tissue).Conditions affecting these tissues fall most commonly into the categoryof periodontal disease. More specifically, the invention is directed atsystems and methods for treating or eliminating recesses that form atthe junction of the tooth base and the gingival tissue, where theseparation of these structures forms a potential space or pocket(referred to as periodontal pockets) in patients with periodontaldisease. This type of therapy could be used both as an adjunctivetreatment in the acute setting in combination with oral surgery orprofessional cleaning, and may also have a use on a chronic, possiblyeven daily, basis for disease prophylaxis (prevention). However, thisinvention may also have other uses in the mouth, such as healing donorgraft sites, optimizing healing for a potential recipient implant site,aiding in healing intraoral wounds, or possibly even as a vehicle fordelivery/concentration of medications directed to the teeth or gums.

BACKGROUND OF THE INVENTION

Gum disease, a very common ailment affecting nearly half of Americansover 30 and over 70% of those over 65, is a condition where chronicinflammation of the gums/gingival tissue can lead to discomfort andpotentially to loss of teeth. Gum disease, called gingivitis (or fordeeper penetration of the process—periodontitis), is usually caused by acombination of factors, including: (a) tissue qualities in the patient'smouth (usually at least partially genetically determined); (b) patienthygiene and home/professional care (i.e., brushing, flossing and dentistvisits); and/or (c) various types of bacterial growth in the mouth(which can often be affected or controlled to a significant degree withproper oral hygiene).

Two salient factors that can contribute significantly to the developmentof periodontal disease are plaque and tartar. Plaque, a sticky bacterialfilm that can accumulate on the sides of teeth, not only can lead totooth decay by increased local acid concentration, but can also irritateand cause inflammation of the gums/gingival tissue. While in most casesplaque can be removed through daily brushing, flossing, and oralrinsing, in some cases the plaque, in combination with minerals in thesaliva, can form a hard, crusty build up at the base of the tooth knownas tartar. This tartar, removal of which often requires professionalintervention, will typically continue to calcify and irritate thegingival tissue, worsening the local inflammation. As a result of thisinflammatory process, the gums can partially separate from the base ofthe tooth, creating pockets next to the teeth that not only expose theroot of the tooth, but also create additional places for bacteria toreside. In many cases, these pockets can become too deep to beadequately cleaned by home care methods, including dental floss,ultrasonic toothbrushes, or pulse lavage irrigation.

The existence of periodontal “deep pockets” can cause a variety ofsymptoms, including bad breath, patient discomfort, temperaturesensitivity, gum recession (i.e., longer appearing teeth), and bleedinggums, but the most insidious effects can include loss of supporting bonestructure which can lead to loss of teeth. This loss of bone structureoccurs as part of the reaction to chronic inflammation that occurs atthe base of the pockets. Since the depth of the pocket cannot typicallybe adequately cleaned by patients themselves, this region remainschronically colonized with multiple forms of bacteria in a situationthat clinically is essentially a chronic low grade infection. Themechanism of the destruction of bone with potential for loss of teethinvolves the effects of the immune system as part of a cascade ofcellular responses to this chronic inflammatory state. Cells involved inthe inflammatory response cause, among other effects, release ofcytokines (secretions from cells of the immune system that affect othercells) as well as other mediators, but the net effect is that bothsupporting bone and the periodontal ligaments (which attach teeth tobone) slowly resorb/disappear. This process continues until the sourceof the inflammation/infection, the bacterial plaque and any accumulatedtartar that resides on the teeth, is cleaned. Given that there is lowerlikelihood of this chronic inflammation occurring when the bacteria havefewer anatomic locations to become sequestered, the risk of bone andtooth loss would be significantly diminished by a treatment that coulddecrease or limit the depth of the periodontal pocket.

Current options available to dental professionals for prophylaxis(disease prevention) and for treatment of periodontitis include (a) homecare and regular dental hygiene and flossing by the patient; (b)periodic deep cleaning in a dentist's office, including scaling and rootplaning; (c) the application of medications to the patient's mouth,including antibiotic rinses, gels, and other delivery systems includingmicrospheres; (d) the use of custom dental appliances impregnated withantibiotics proximate to the inflamed locations; and/or (e) theemployment of various oral surgical procedures, including flap surgery.Flap surgery involves lifting the gums to remove tartar and/or depositsand allowing the surgeon direct access to the base of the tooth, andthen suturing the gums back to result in significantly more shallow(less deep) periodontal pockets. In many instances this flap surgeryoption can result in more gum recession (i.e., there is less gum tissueleft, so teeth appear longer) or the need for bone or tissue grafting(i.e., taking bone or gum tissue from elsewhere to pack into a smallarea to promote tissue regeneration, to allow connective tissue tore-grow).

Despite the best intentions of the dental health professionals, and goodhome care efforts by the patient, traditional treatments forperiodontitis can slow but often not halt disease progression. Even withbrushing and flossing, and even with mechanical assistance fromappliances such as the ultrasound toothbrush (e.g., SONICARE) and pulselavage (e.g., WATERPIK) devices, the depths of the pockets, especiallywhen they get to be greater than 4-6 mm, cannot typically be cleanedthoroughly by the patient, and professional cleaning is often required.In most instances, this type of deep cleaning involves either some sortof discomfort, or administration of local anesthesia, and is not withoutsignificant cost.

Aside from the anatomical challenges of cleaning the depths of theperiodontal pockets, another issue is that the chronic colonization ofthe pockets involves multiple forms of bacteria, and even a professionalcleaning is often temporary at best. Even if a dental professional wereable to get to access the bottom of the pocket and scrape it clean, thatarea will typically be re-colonized with bacteria almost immediately.Moreover, attempts to decrease the bacterial load in the pockets bylocally applying antibiotics with dental appliances have been heretoforeunsuccessful, with numerous studies showing that such medicationapplications do not typically reach the source of periodontal infectionsat the base of the tooth.

In cases of periodontal pocket formation that require surgicaltreatment, additional challenges exist. Aside from the patientdiscomfort and expense, even with flap surgery, since the mouth is notmade sterile, there are persistent bacteria at the base of the flap atthe time of surgery. Moreover, the gingival flaps are often repairedwith sutures, which are themselves foreign bodies that cause a componentof tissue reaction/inflammation, and the swelling component of theinflammatory reaction prevents egress/outflow of tissue fluids, creatingfurther areas where bacteria can reside.

BRIEF SUMMARY OF THE INVENTION

One aspect of the present invention includes the recognition of thevarious issues and challenges in treating periodontal disease (as notedabove), and the realization of a need for improved oral appliances andrelated methods and techniques to resolve issues currently presentedwith such traditional treatments. The present invention includesdevices, systems and methods to desirably optimize the healingcapabilities of inflamed tissues in the mouth to promote improved softtissue healing using a method that can be relatively simple to apply ina manner that desirably does not involve significant patient discomfort.

As opposed to the eventual resolution that occurs with healing in anacute wound, the cellular events that occur in the setting ofperiodontal pocket formation typically reflect those that occur with achronic wound. From a general perspective, successful wound healing canoccur when there are more factors favorable for, rather than against,the healing process. In wounds that become chronic, the factors for andagainst healing reach a balance called stasis, where little changes. Onefactor germane to understanding non-healing wounds is that the tissuerepair process requires more oxygen and nutrients than required formaintenance of tissue. Given that more circulation and cell division arerequired for repair to occur, the focal swelling associated with chronicinflammation can be more of a hindrance to the repair process aslocalized swelling can restrict blood flow to the tissues. In this stateof relative hypoperfusion (i.e., less than adequate blood flow), thetissues around the wound are typically less successful at providingoxygen and nutrients needed to promote healing. Factors that would favordevelopment of additional blood flow to the area, along with allowanceof egress (removal) of excess tissue fluid, would desirably create anenvironment where the local tissues are also better able to fightinfection and close/repair the periodontal pockets naturally with localtissue ingrowth. Similarly, factors that would decrease swelling andencourage angiogenesis (i.e., ingrowth of blood vessels to the area)would desirably favor wound healing.

The present invention, which can in various embodiments include thefabrication of a custom oral appliance to direct the application ofnegative pressure wound therapy (NPWT) or vacuum therapy to one or moreareas within the mouth, is proposed to, among other potential uses,create more optimal conditions to allow gingival tissue to heal back tothe base of the teeth, and to minimize the clinical sequelae ofuntreated periodontal pocket formation. In various embodiments disclosedherein, an improved oral appliance and treatment method are providedthat represent significant advancements in the fight against periodontaldisease. Given the relatively well perfused (i.e., good blood supply)character of typical gingival tissues, along with a generalizedsignificant baseline of resistance to infection in these tissues (i.e.,periodontal surgery in the contaminated oral environment is often donewithout antibiotics), the current invention could likely augment thefactors affecting wound healing that desirably change cellular events ina favorable manner.

One objective of the present invention is to provide an improved oralappliance device and method that would eliminate or resolve many of thechallenges experienced by dentists, oral surgeons and/or other healthcare professionals in their treatment of periodontitis. In at least oneexemplary embodiment, a custom oral appliance can be provided thatcontacts at least a portion of teeth and/or soft tissues inside of apatient's a mouth to provide negative pressure to some or all of adiseased area and/or the surrounding anatomy. The negative pressure orvacuum environment will desirably create a focal or generalized pressuregradient that can draw fluids, solids and/or other exudates from aspecific area of the gum tissue at the base of the teeth, or evenpossibly other areas within the oral cavity, and may optionally draw gumflap tissue closer to, proximate to and/or into intimate contact withsome or all of the exposed teeth to facilitate healing and/orreattachment in a desired manner. This healing and/or reattachment mayoccur through a combination of the applied negative pressure (whileusing the custom oral appliance) and various natural physiologicalhealing responses of the body. In various embodiments, the negativepressure gradient will desirably assist with removal of drainage (tissueexudate) and/or other fluids/materials from a diseased area, it mayinduce an angiogenic response or reaction to the localized gum tissuelayers to potentially create new microvasculature for improved wasteremoval and/or blood flow, and it may induce mitosis (i.e., celldivision) to repair/replace damaged tissue and/or enhance attachment ofthe gum tissue to the exposed teeth.

In one exemplary embodiment, the improved negative pressure dentalsystem comprises a custom oral appliance, a single or multi-lumen tubesystem, and a source of negative pressure (i.e., a vacuum machine).

In another exemplary embodiment, the custom oral appliance may comprisean upper and/or lower custom oral appliance which covers some or all ofthe dentition/dental arches, and which can be manufactured at leastpartially from a polymeric material. The custom oral appliance caninclude an inner contact surface and an outer surface. The inner contactsurface could desirably be in contact with some or all of the teeth,gingival (gum) tissue, and/or palate, and the outer surface could be incontact with various other tissues within the mouth such as the tongue(lingual surface), the cheeks (buccal surface), and/or the lips (labialsurface), depending on the structural aspects of the patient'sindividual appliance. The negative pressure environment could be appliedto the tissues in contact with the inner surface of the appliance, whichcould include equal and/or unequal negative pressure application (i.e.,include pressure transfer across the teeth due to the spaces between theteeth), and/or the equal/unequal distribution of pressure could beprovided by a channel or other feature created along a margin of thetooth and gum (commonly referred to as the gingival sulcus), or otherdesired area, depending on the location of the intraoral condition beingtreated (with one example being to facilitate healing from a soft tissuedonor site in the palate for gingival repair via soft tissue grafting).The application of negative pressure proximate to the gingival sulcuswould desirably serve several functions in the treatment of periodontalpockets, including reducing local tissue edema, removing tissue fluidsfrom the depths of the pockets, and/or providing a pressure gradient forbringing healing cells to this region.

Various embodiment can include methods of fabricating an oral appliancewith a channel or void facing towards and/or positioned proximate to atargeted anatomical surface, such as a surface of the tooth and gums atthe level of the gingival sulcus. Desirably, features can be providedthat reduce and/or eliminate the vacuum pressure in the appliance duringdevice removal, such as pressure release valves and/or flexible tabs onthe appliance and/or tubing, which would desirably make the applianceeasier for the patient to apply and/or remove. If desired, there may beat least one aperture that extends from the front of the appliance forthe application/delivery of negative pressure to the inner surface ofthe appliance. In various embodiments, the polymer(s) utilized inmanufacturing the appliance (if any) will desirably not exhibit any odoror taste, can be substantially flexible and will desirably containproper tensile and/or impact properties. The polymeric material may alsobe made clear or opaque.

In another exemplary embodiment, a single-lumen or multi-lumen tubesystem may include an oral appliance tube adapter, a single ormulti-lumen tube, a transition tube, a transition adaptor, and anegative pressure tube adapter. The oral appliance tube adapter may beattached and/or connected to the oral appliance and may contain at leastone or more lumina (i.e., longitudinally extending openings throughand/or within the tube) to extract the exudates/tissue fluids and/ordeliver the negative pressure surrounding the oral appliance, which invarious embodiments may include a capability to monitor the level ofpressure being applied (i.e., through one or more ancillary lumen orlumina). The transition tube may be a different size, configuration andfunction than the multi-lumen or single-lumen tube (i.e., one of thefunctions of the transition tube may be to connect to the negativepressure machine to the appliance). The transition adaptor may be acomponent that facilitates the transition between the multi-lumen tubeto the transition tube.

In another embodiment, the negative pressure vacuum machine may beequipped with custom features or a commercially available negativevacuum machine may be used. For example, a commercially availableportable suction machine can be used, such as the Medline Vac-AssistSuction Aspirator (Medline Industries, Inc. of Mundelein, Ill.).Although Medline is one example, many hospitals carry various vacuummachines of many different manufacturer types, which may also besuitable for use with the present invention, as well as permanentlyinstalled vacuum systems (which often include access ports proximate tomultiple hospital beds). The portable suction machine may includeminimal controls such as delivering a negative pressure range of 25-250mmHg, can have continuous and/or intermittent operation, can carry astored power supply and/or be rechargeable, and will desirably be of alow weight (i.e., approx. 5 lbs. or less to 25 lbs.). Alternatively, acustom negative vacuum machine may be modified to improve portability,to use battery power, to be designed for single use, and/or to belightweight in order to make the application of negative pressuretherapy less cumbersome.

In another embodiment, the negative pressure oral system may comprise animportant part of a treatment program for periodontitis. After a dentalprofessional confirms the diagnosis of periodontitis or periodontalpocket formation in a patient, one iteration of implementing thistreatment strategy could include obtaining an impression of a patient'supper and/or lower teeth, and then creating a cast of a patient's upperand/or lower teeth from which the oral appliance could be fabricated. Inorder to focus the application of negative pressure to the gingivalsulcus, a channel could be created in the appliance by applying a typeof periodontal dressing to the gingival sulcus of a patient's dentalcast (i.e., the model of the patient's dentition) with a focus on theareas to be treated, whether upper and/or lower arch, and whetherlingual and/or buccal surfaces, fabricating an oral appliancecorresponding perfectly or at least partially to the patient'sindividual anatomy. This appliance, which could be connected by a singleor multi lumen tube(s) to a negative pressure machine with adjustablesettings, could function to create a negative pressure environment asdescribed herein to desirably optimize the local periodontal tissueconditions to maximize the chances of removing exudate from the pocketsand allowing the negative pressure gradient to bring healing cells intothe area. A controlled negative pressure environment could have utilityin effecting healing of the periodontal pockets, but also could be usedin conjunction with other oral surgical procedures such as root canalsand/or placement of mandibular anchors or implants, healing of donorsites from where tissue is harvested for gingival grafting procedures,and/or could also have a use in a prophylactic capacity (i.e., diseaseprevention) whereby intermittent regular use, possibly combined withrigorous home care, could lead to either improvement of or prevention ofa worsening of periodontal pocket formation.

In various embodiments, the devices, systems and methods describedherein could have utility for use the first few days after a routinescaling, where the roots of the teeth have just undergone mechanicalplaque removal, and the process of scaling may have caused a low levelof trauma to the gingival tissues. Application of the negative pressuresystem acutely after this scaling, in the setting of the gingivaltissues healing from the manipulations of the cleaning process, couldoptimize the healing process and lead to a decrease in pocket depth, theachievement of which is the goal of flap surgery.

In other embodiments, such as alluded to above, the negative pressureoral systems, devices and methods described herein may have particularutility in the treatment of oral wounds resulting from injuries and/orsurgical procedures, including wounds resulting from root canal surgery,dental implantation procedures, graft donor sites and/or dental graftingprocedures. If desired, the oral appliances described herein may beutilized to prepare an area for surgery and/or cleaning (i.e., to reduceinflammation and/or control infection in tissues targeted for surgery orcleaning and/or adjacent to intended surgical sites) as well as to treatand/or manage surgical sites after surgical procedures. If desired, thevarious teachings described herein may be utilized in treating surgicalanchor implant sites and/or grafting sites, where healing of the site isdesirous prior to final implantation of a surgical implant and/or graft,as well as after the surgical procedure to promote healing of affectedtissues. Another potential benefit of using the oral appliance may bethat, during the period of use, there could be a potential for thesystem to include features that modify neuromuscular feedback that couldpossibly minimize bruxism (involuntary jaw clenching) that untreatedcould have a deleterious effect on the periodontal ligaments (thatattach the teeth to the bones).

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 depicts a top view of one embodiment of a negative pressure woundtherapy on a limb;

FIG. 2 depicts a cross-sectional view of one embodiment of a negativepressure wound therapy on a limb;

FIGS. 3A through 3C illustrate an exemplary time healing response of anextremity wound using negative pressure wound therapy;

FIG. 4A illustrates a partial cross-sectional view of one embodiment ofa healthy tooth and adjacent gum tissues;

FIG. 4B depicts a magnified partial anterior view of various structuressupporting the tooth base, including gingival tissues; and

FIG. 4C illustrates a magnified partial cross-sectional schematic viewof a healthy tooth and adjacent gum tissues;

FIG. 4D illustrates a further magnified partial cross-sectional view ofthe healthy tooth and adjacent gum tissues of FIG. 4C;

FIG. 4E illustrates a partial cross-sectional schematic view of oneembodiment of a tooth and adjacent gum tissues suffering fromperiodontal disease;

FIGS. 5A-5C depict various schematic views of a cast/model of apatient's dentition that could be utilized in forming an oral appliance;

FIG. 6A depicts one embodiment of an augment that could be applied tothe cast of the patient's dentition and/or gum line to help form thechannel whereby the negative pressure would be applied;

FIGS. 6B and 6C depict one alternative embodiment of an augment appliedto the cast of the patient's dentition and/or gum line also to help formthe channel whereby the negative pressure would be applied;

FIG. 7 depicts one exemplary embodiment of a dental impression traycontaining a pliable impression material that can be placed over aregion of interest of a patient's dentition;

FIGS. 8A-8D depict various views of one alternative embodiment of adental impression tray containing a pliable impression material that canbe placed over a region of interest of a patient's dentition;

FIG. 9 depicts various anatomical references for typical tooth positionswithin an oral cavity;

FIG. 10 depicts another alternative embodiment of a dental impressiontray containing a pliable impression material that can be placed over aregion of interest of a patient's dentition;

FIGS. 11A-11D depict one exemplary embodiment of an oral appliance foruse in negative pressure oral therapy;

FIG. 12 depicts one exemplary pressure distribution path for negativepressure in the embodiment of FIG. 11A;

FIG. 13A depicts a partial cross-sectional schematic view of a channelof a negative pressure oral appliance and associated patient anatomy;

FIGS. 13B through 13F depict partial cross-sectional schematic views ofalternative embodiments of negative pressure oral appliancesincorporating various channel shapes and/or sizes, with associatedpatient anatomy;

FIG. 14 depicts a cross-sectional perspective view of one embodiment ofa multi-lumen tube;

FIGS. 15A and 15B depict one alternative embodiment of an oral applianceincorporating a dual tubing and dual channel arrangement; and

FIG. 16 depicts a view of one exemplary embodiment of a negativepressure oral appliance, including an upper arch prototype.

DETAILED DESCRIPTION OF THE INVENTION

Given that negative pressure wound therapy has shown great utility intreatment of acute and chronic wounds and of burn injuries of the torsoand extremities, the present invention seeks to incorporate similarbenefits of therapies involving negative pressure environments to effecthealing in the oral space. The application of negative pressure in thevarious manners described herein can desirably act to convert a chronicstatic situation (where periodontal pockets can be thought of achronically infected tissue) into one with greater healing potential,and does so in a manner that is relatively comfortable for the patientto tolerate, and could help patients avoid surgical procedures that arepotentially painful and expensive. The principals of negative pressurewound therapy, which have shown great effectiveness in wounds that areparticularly challenging, such as in poorly vascularized tissues inorthopedic wounds with exposed tendon, bone, and cartilage, incombination with specially designed and/or constructed orthoses todirect and/or concentrate such therapies in one or more desiredlocations, show significant promise to treat the oral cavity. Suchtherapies can desirably employ negative pressure (i.e., a partial orfull vacuum) to function to remove drainage (i.e., tissue exudate),while the negative pressure forms a gradient, bringing healing cellsinto the wound, and promotes angiogenesis (formation of new bloodvessels) in one or more treated areas. Aside from removing tissueexudate, the negative pressure may also encourage wound contraction(i.e., bringing wound edges together), a process that effectivelyreduces the number and/or size of places that might be favored forunwanted bacterial growth.

FIGS. 1 and 2 depict a relatively simplified view of a wound surface andassociated prior art negative pressure therapy appliance, currently usedfor treatment of externals wounds of an extremity such as an arm or leg.The external view of FIG. 1 shows a skin surface 10, an ellipticallyshaped (in this case) wound 50, an adhesive dressing 130, and a trackpador semi-rigid pad 150 for application of negative pressure outside thedressing 130, and the path of egress of any withdrawn fluids, andthrough which the negative pressure is applied. This exemplary extremityon a cross-sectional view includes skin surface 10, which overlies fatlayers 20, which in turn typically covers muscle layers 30, with anunderlying core layer of bone 40. A wound surface 50 in FIG. 2 is shownin this schematic extending deep only to a muscle layer. However, incases where NPWT has effected healing in the extremities and torso, thiswound surface can extend deep to tissues with less circulation that areharder to heal, like tendon, bone 40, and/or cartilage. These woundsurfaces would typically be present after debriding tissues that areclearly non-viable (since even negative pressure cannot often not bringthem back to viability), and this schematic is offered as a way toclarify how negative pressure can be applied to a wound surface. Afterdebridement of the non-viable tissues, there is usually a component ofinflammation, which is the cascade of cellular events whereby the bodymobilizes its defenses to both fight infection and to heal tissueslocally. Since there is more often than not bacterial contamination, ifnot frank infection, usually a course of antibiotics is required.However, after the non-viable tissues (which are places where bacteriacan reside) are removed, and usually after a limited course ofantibiotics, healing in the negative pressure environment can oftencontinue without and independent of antibiotic therapy. A successfultreatment using NPWT, for example, could be demonstrated by the surfaceof the wound being eventually covered with a reddish tissue calledgranulation tissue (for an example of this healing, see FIGS. 3B and3C). If further tissue necrosis has occurred (for example, if anotherpiece of bone or tendon at the depth of the wound has becomenecrotic/non-viable), the granulation tissue will typically not coverthe necrotic surface and repeated debridement will often be needed.

As noted above, after debridement, a suitable negative wound pressuretherapy device can be applied to the wound. As best seen in FIG. 2, anexisting NWPT device, pictured in cross-section, can be placed againstthe wound surface 50, with a significant portion of the wound adjacentto a pressure distribution member 110 (in this case a spongy foammaterial) which desirably transfers the vacuum pressure from a deliverytube 120 to the underlying wound surface 50. Desirably, the pressuredistribution member 110 will comprise a flexible material having anabundance of open cells and/or air passages (i.e., an open cell,“spongy” surface), which allows the vacuum pressure to be transferredand applied evenly to large areas of the wound surface 50 withoutdrawing the delivery tube 120 and wound surface 50 into direct contactwith each other. The member 110 in this embodiment could be selectedand/or shaped to desirably fit approximately into the wound cavity andto evenly distribute the negative pressure environment. An adherentdressing 130 can be placed on top of the member 110 and surrounding skinsurface 10. The adherent dressing 130 will desirably comprise anairtight material, which in this embodiment could be a thin filmmaterial which is desirably flexible and sticky on at least one side.The adherent dressing 130 can be applied to the skin surface 10, to sealin the wound environment, with a small hole (not shown) made in theadherent dressing. A semi-rigid pad 150 (i.e., a “trackpad,”commercially available from Acelity L.P., Inc. of San Antonio, Tex.,USA) can be placed over the small hole in the adherent dressing,providing an air tight connection between the delivery tube 120 and themember 110, which desirably applies the negative pressure to the wound.The net effect of this arrangement is that the surfaces of the wound incontact with the spongy member 110 are desirably subject to a generallyuniform vacuum pressure, without significant concentration of vacuum inany specific area. While this information is provided for perspective onhow negative pressure is typically applied to a generic extremity wound,including the requirement for both an adherent dressing to maintain thesuction seal for negative pressure, and for a sponge to equallydistribute the negative pressure over the treatment surfaces, some orall of these elements may not be required for treatment of wounds withinthe oral cavity, as will be detailed below.

In wound applications of this generic type, the use of such spongymaterials is extremely important to the proper application of woundtherapy. Without the spongy intermediate material, the directapplication of vacuum pressure from the trackpad to the underlying woundsurface would typically concentrate an excessively high vacuum pressureto a small area of the wound bed, and likely draw some portion of thedamaged tissues into the opening 160 of the trackpad, which wouldfurther exacerbate and compromise the wound. Moreover, the negativepressure applied through the hole would not be properly distributed tothe remainder of the wound surface (i.e., to areas not under the hole).As noted above, in the present invention, since the teeth canpotentially act as a scaffold for various embodiments, and since themoist surfaces in the mouth are optimal for forming a seal, the spongymaterial may not be needed in various embodiments.

Negative pressure wound therapy can be used in a number of woundsettings that would ordinarily be challenging to address. In manyinstances the wound environment is “challenging” because of the presenceof significant amounts of necrotic tissue (which will often requiredebridement) in various locations within or surrounding the wound.Healing can also be challenging due to other factors including thepresence of minimal local blood supply, significant wound depth withpotential for drainage issues, and the limited availability of localtissues for potential transfer to fill the post debridement defect.

To illustrate how NPWT can be very useful in wound environments that arechallenging, consider the example illustrated in FIGS. 3A through 3C ofa wound on the dorsal aspect of a foot which, after debridement ofnon-viable tissues, shows exposed bone, which is a poorly vascularizedtissue type. The options for salvage of the type of foot woundillustrated would be extremely limited, and absent NPWT, salvage of thefoot as pictured would be unlikely to occur. After debridement, a spongewas cut to fit the contour of the wound, and it was placed over thewound. Subsequently, an adhesive dressing was applied over the contouredsponge and a track pad (as described above) was applied to a small holemade in this adhesive dressing. Through the application of negativepressure to this wound surface, tissue exudates were removed, and agradient was created to draw healing tissues to the surface, thusallowing for tissue growth to occur over the exposed bone with healingdocumented in the interval figures of 3A through 3C. With particularreference to FIG. 3A, exposed metatarsal bones 61 can be seen afterdebridement, with healing evident at three weeks post treatment (i.e.,partially exposed metatarsal bones 62 of FIG. 3B) and at five weeks posttreatment (i.e., see minimally exposed metatarsal bones 63 of FIG. 3C).

Alternative treatment options for the type of wound shown in FIG. 3 aretypically suboptimal. For example, limitations of other treatmentoptions could include: (1) local tissue transfer is limited by theavailability or lack thereof of local tissue; (2) free tissue transfercould require a plastic surgeon to perform this type of procedure, aservice increasingly difficult to arrange and reimbursed either poorlyor not at all by insurance companies, and could leave the patient with asometimes unsightly tissue mass on the dorsal foot; or (3) theapplication of moist dressings and “hope” that some healing can occurbefore the bone becomes non-viable—a technique that is rarelysuccessful. There are countless instances where NPWT has provided forlimb salvage in extremity wounds.

Some wound situations are more challenging than others for healing tooccur. Especially in situations with poor local blood flow, the normalphysiologic responses, absent modalities like negative pressure woundtherapy or other more aggressive, costly, and potentially painfulsurgical techniques, can be ineffective in bringing about healing.Fortunately, with regards to the current invention, since there isbetter vascularity of gingival tissues, the currently describedinvention would likely be effective with a treatment schedule thatrequires patient participation for significantly less time than isrequired for wounds of the extremities and torso. For reference;gingival flap surgery usually demonstrates adequate healing in 5-7 days,so shorter intervals of NPWT could significantly optimize healing ofsuch wounds in the oral environment.

Various embodiments of the present invention include devices and methodsof use that seek to apply various advantages of negative pressure woundtherapy in a unique and unusual manner to one or more periodontalapplications. While many wounds in the oral cavity may have the capacityto heal faster and with less scarring than similar wounds in other partsof the body, the healing of some tissues in the mouth, especially therepair and/or regeneration of tissues at the base of a periodontalpocket, are more difficult.

Periodontal tissues include a variety of types, including soft andmineralized tissues which form the connection between the teeth and theunderlying bony structures. Many of these structures are illustrated inFIG. 4A. The tissues that cover a surface are called epithelial tissues,and epithelial cells are on the surface of the gingival tissues, andalso line the periodontal pockets when they form. The periodontalligaments (FIG. 4A, 128) are connective tissue structures includingneural and vascular elements that connect the cementum covering thetooth root (FIG. 4A, 126) to the alveolar bone (FIG. 4A, 170). Thisconnection is referred to as the dentogingival junction, and maintainingits integrity is essential in order to preserve the periodontalligaments which anchor the teeth to the bone. However, this junction isoften damaged and/or destroyed by the chronic inflammatory processrelated to periodontal diseases, and in order to effectively control thedestructive effects of chronic periodontal diseases and to regeneratethe lost tissues to some degree, the dentogingival junction willdesirably need to either be restored, or to have tissue loss mitigated.

In cases of chronic periodontitis, the dueling forces of bacterialcolonization/chronic infection vs. the immune/healing response of thebody are at a standoff, with little improvement left untreated. However,beginning the repair process usually involves professionalcleaning/scaling of tooth surfaces in the depths of the periodontalpockets. As a response to this cleaning, the tissues are often irritatedcausing a temporary increase in inflammation, and as a result, thecellular events involved in wound healing are amplified. In the acutesetting as such, a number of aspects of the inflamed tissues can bemodified by application of NPWT to optimize healing potential asdescribed herein. The irritated/wounded tissues become more permeable,and in many instances where some bleeding has occurred, clot forms.Inflammatory cells invade the area, and a cascade of cellular eventsoccur, including the migration of fibroblasts into the area, along withangiogenesis, formation of new blood vessels, from endothelial cellsthat migrate in from adjacent broken blood vessels. These healing cellsform a tissue called granulation tissue (in a manner similar to thetissues repairs depicted in the foot example in FIGS. 3A through 3C, buttypically on a smaller scale in gingival tissues). Next, the migrationof epithelial cells covers the denuded tissue surfaces or forms ajunction at the tooth-tissue interface. Lastly, maturation of thehealing tissue matrix can be accompanied by contraction or scarring.NPWT can function in these situations to allow for increased egress oftissue fluids, decreased edema, and the negative pressure gradient canincrease angiogenesis.

The healing potential of periodontal pockets, while influenced bymultiple factors, is also related to the depth of the process. The levelof the alveolar bone is referred to as the crest of the bone (FIG. 4A,170). A periodontal pocket that goes above the bone (supracrestal) isgenerally less severe than one that goes below the level of the bone(subcrestal), but also different tissue types can be involved.

Gingivitis is described as the inflammation that is limited to thegingival tissue, not extending below the crest of the alveolar bone(FIG. 4C, 127) with this level demarcated by crestal periodontalligament fibers. At this level of disease, there is less disturbance tothe soft tissues supporting the cementoenamel junction. These anatomicalstructures are illustrated in FIG. 4A, showing the cementum 126 whichcovers that anatomic root of the tooth, along with the cementoenameljunction 124 which is where the enamel meets the cementum, and theperiodontal ligaments 128 which help anchor the tooth to the underlyingalveolar bone. If gingiva is removed by surgical excision, granulationtissue and epithelial cell migration from the adjacent mucosal tissuewill desirably achieve restoration. The granulation tissue rebuilds themajority of the gingiva in which fibers are arranged functionally in thedirection of their tensile strength resulting in a functional scar.Epithelial cells migrate across the granulation tissue. In that theprocess of healing this type of wound involves a component ofinflammation, along with need for new tissue ingrowth, which healingcould be accelerated by use of NPWT as described herein.

When periodontal tissues have been damaged more profoundly to the levelwhere the condition is considered periodontitis, the healing is oftenmore complicated compared with simple gingivitis cases. Different celltypes are required as compared to gingivitis cases, but elements of theprocess, including involvement of an inflammatory cascade, need fortissue regrowth and angiogenesis, often remain the same. The tissuerepair process can likely be modulated by NPWT in a favorable manner. Inthe healing process, a desirable outcome of use of NPWT could be toallow the negative pressure environment, with the propensity to inducewound contraction, to encourage the re-formation of junctionalepithelium (epithelium in contact with the base of the tooth, animportant component of periodontal defense mechanism against infection)and periodontal ligament tissue.

Various embodiments disclosed herein incorporate features that canutilize various aspects of the oral anatomy to facilitate treatment ofintraoral conditions, including the ability to distribute negativepressure and negative pressure effects to one or more areas within theoral cavity, including an equal and/or unequal application to a desiredperiodontal pocket and/or to various tissues surrounding an affectedarea. Improved oral treatment systems can optionally include variousmechanical features in the oral appliance that could accomplish similarobjectives, including the ability to equally distribute negativepressure to a desired area. In various embodiments, NPWT can be aneffective adjunct in optimizing treatment for oral conditions likeperiodontal pocket formation, usually in conjunction with treatment andprofessional cleaning/debridement performed by an oral healthcareprofessional. Moreover, various oral wounds may heal faster with lessscarring than wounds of the extremities and torso due to additionalfactors such as the presence of saliva, specific microflora of the oralcavity, and/or favorable physiologic properties (i.e., appropriate pH,higher concentration of lymphatic cells). Therefore, given the morerapid healing of gingival/periodontal tissues, NPWT can be an importantadjunct in a treatment program.

FIG. 4A illustrates a partial cross-sectional views of a healthy tooth(i.e., an adult human molar) and associated gum tissue. In thisembodiment, the tooth 100 can be separated into an upper crown layer 115and a lower root layer 118. In the tooth, an exterior layer of enamel122 surrounds an inner layer of dentin 130, which in turn surrounds aninterior pulp layer 140 which contains various vascular and nervenetworks. The gums or gingiva 160 surround the tooth 100, with anunderlying layer of alveolar bone 170 deep to the gums 160 and rootlayer 118 of the tooth 100.

As previously noted, the gum tissues 160 surrounding the tooth 100 inFIG. 4A appear relatively healthy, with little space between the gumtissue 160 and the root layer 118 of the tooth. As best seen in FIGS. 4Band 4C, the gums or gingiva are composed of an attached gingival portion180 and an unattached gingival portion 185. The unattached gum tissue isreferred to as the “free gingiva” or “marginal gingiva,” which is theunattached portion of the gingiva that surrounds the tooth in acuff-like manner. The unattached gum tissue fits closely around thetooth but is not directly attached to the tooth—which allows a dentalprofessional to stretch the gum tissue away from the tooth surface usinga periodontal probe to measure the depth of this space which, when itbecomes deeper, is the periodontal pocket. The unattached gum tissueforms a minimal soft tissue wall within a gingival sulcus, where theunattached gum tissue meets the tooth in a thin rounded edge called thegingival margin 200 that follows the contours of the teeth. Alsodepicted is the alveolar mucosa 205, the mucogingival junction 190(i.e., the upper edge), interdental grooves 210, interdental papilla 215and the free gingival groove 220.

FIGS. 4C and 4D depict various anatomical features in proximity to thegingival sulcus 250, which is the space between the unattached gums andthe tooth surface. The gingival sulcus 250 in healthy individuals can bea V-shaped shallow space around the tooth, extending approximately 1-3mm (i.e., a normal, healthy depth). At the base 255 of the sulcus isjunctional epithelium 260, which is tissue that lines surface of thetooth enamel 122, where the attached portion gum or “attached gingiva”is attached to the root of the teeth. The junctional epithelium (shownin FIG. 4C at 129 and in FIG. 4D at 260) is a specialized type ofepithelium that attaches to the tooth surface. Usually, the attachedgingiva is tightly connected to the cementum 126 on the cervical thirdroot and to the periosteum (connective tissue cover) of the alveolarbone 170—it lies between the free gingiva 185 and the alveolar mucosa205 (i.e., alternatively it may lie between the free gingival groove tothe mucogingival junction). The attached gingiva provides a variety ofimportant functions, including withstanding mechanical forces frommastication, speaking and/or tooth brushing, and also prevents freegingiva from being pulled away from the tooth when tension is applied tothe alveolar mucosa. The periodontal ligament 128 is a group ofspecialized connective tissue fibers that attach the tooth to thealveolar bone 170 within which it sits.

The clinical picture of an exemplary tooth 300 affected by periodontitisis illustrated in FIG. 4E. As a result of chronic inflammation, theperiodontal pockets can deepen with the pathologic anatomy illustratedin this schematic diagram. While the reasons for periodontal pocketformation are multifactorial, the basic process is characterized by avicious cycle: the bacteria have a place to hide at the base of thepocket, essentially creating a situation of a chronic low gradeinfection. The reaction of the body to this process involves a cascadeof events we know of as inflammation, and one of the sequelae of thischronic inflammation is that the tissue attachments become lessadherent, and as a result there is further separation of soft tissuesfrom the base of the tooth. The deeper the pocket becomes, the moredifficult it is to clean, and the more inflammation occurs, thuscontinuing the cycle. To relate to FIG. 4E, the affected gingivaltissues 310, as a result of this chronic inflammation, begin to detachfrom the surface of the tooth 300 and the enamel surface 122. Thebacterial biofilm known as plaque 330 can extend to the base of thetooth and as the tissue attachments recede, to the cementum 126 which,with its irregular surface, provides even more places for bacterialplaque to exist. The depth of the pocket (from 200 to 320) can bemeasured by the dentist's periodontal probe, and once this distance ismore than 3-4 mm, the pocket is difficult to clean even with aggressivehome care. These periodontal pockets can be present chronically, as theopposing factors of healing and bacterial proliferation are at astandoff. Therefore, the need for an additional modality such as NPWT isillustrated by the fact that the natural history of periodontal pocketformation (especially untreated) is to worsen over time.

As the gingival sulcus 320 deepens, with resultant breakdown of theconnective tissues and resorption of bone 170, there is less periodontalligament tissue 128 to keep the teeth in place. The gingival sulcus cancontinue to deepen as the soft tissues and periodontal attachment fibersare destroyed, to depths sometimes reaching the alveolar mucosa.Recession (i.e., less gum tissue covering the base of the tooth, makingthe tooth appear longer) can occur, and along with destruction of theperiodontium (the tissues that support and surround the teeth),including the bony tooth socket, with a potential for increased toothmobility, which left untreated can result in tooth loss.

In various exemplary embodiments, an improved negative pressure dentalsystem can comprise a custom oral appliance, a single or multi-lumentube system, and a negative pressure generating device or machine. Invarious embodiments, the negative pressure dental system may include avariety of components, and various component arrangements andcharacteristics of the intra-oral environment can obviate any need fordistributive foams, sponges and/or special dressings/fillers, which aretypically used to equally distribute the negative pressure with vacuumand/or low pressure treatment of other anatomical regions such as theextremities.

In various disclosed embodiments, an oral appliance can be designed tointeract with the oral mucosa, saliva and/or other anatomical structuresin the mouth which, in combination with various mechanical structuresand/or other features of the appliance, can provide a sufficient seal inorder to maintain the application of negative pressure to the surfacesbeing treated. However, if desired, such supplemental tools such assponges or special dressings or fillers could be incorporated into thevarious embodiments described herein.

As disclosed and described, the various embodiments may include oralappliances of having sufficient structural integrity to maintain adefined shape, but which are still desirably sufficiently flexible tocreate a sealed local environment (i.e., with the local moisture and/orvarious tissues) to effectuate a useful negative pressure environment.The negative pressure environment desirably facilitates egress of tissuefluids, reduction of edema (excess tissue fluid often associated withchronic inflammation) and due to the moist environment of the mouth,there is less risk of tissue dehydration/desiccation or cell death ascompared to other areas in the body. Moreover, the oral mucosa isrelatively well perfused, such that the added modality of the negativepressure environment can modify local conditions to promote healing andpotentially close the space at various depths of the periodontal pocket.

Desirably, the disclosed systems and methods will bring healing cellsinto the depth of the periodontal pockets which are a physiologicallydisadvantaged area of the oral cavity. Just as this gradient can bringhealing cells to cover an exposed bone in the extremities, the healingcells can help restore or reestablish the attached gingiva to the toothsurface with the formation of tissue that approximates long junctionalepithelium, desirably providing a nearly normal gingival sulcus at thesame healthy level.

In various embodiments, an improved negative pressure dental system orperiodontal suction system may further comprise additionalconsumer-oriented features, such as (1) an appliance somewhat flexiblefor optimal patient comfort, yet which allows contact between theappliance and the gum surfaces; (2) an option for applying and/ormodifying suction that is tolerable to the patient; (3) an appliancedesign that makes it easy for the patient to place and remove theappliance; and (4) an appliance design that is tolerable to wear forhours at a time, preferably including the opportunity to wear theappliance while sleeping.

In various embodiments, an oral appliance for use with the varioussystems and methods described herein may comprise an upper and/or lowercustom oral appliance. The oral appliance may be formed via a directimpression from the patient's oral cavity (i.e., similar to boiling andforming a sports mouth guard), or a mold/impression of the patient'sdentition may be taken, with the oral appliance formed from a dentalcast (model of the patient's teeth) of the patient's dentition which isformed from that mold/impression. If desired, a dental professional orother individual can fabricate the appliance, which may include the stepof augmenting the dental cast with periodontal dressing/filler at orproximate to the gingival sulcus on the model. In various embodiments,this periodontal dressing could be applied to the dental cast to helpshape the appliance to allow for a channel to focus the negativepressure on the gingival sulcus (or on other areas in the mouth asindicated), but the periodontal dressing may also be applied in thepatient's mouth at the time of the dental impression as another optionfor fabrication of the appliance.

FIGS. 5A through 5C depict various schematic views of a cast of apatient's dentition 400, which could be utilized in forming an oralappliance for use in various of the embodiments described herein. Asbest seen in FIG. 5C, an anterior deep pocket 410 and a posterior deeppocket 420 have formed in gum tissues adjacent to a patient's rightmandibular central incisor 430. In various embodiments, an augment (seein FIG. 6A at 450, and also referenced above as a “periodontaldressing”) can be applied directly to the patient's dentition at the gumline (i.e., the gingival sulcus) prior to making the dental impression,or to the dental cast at the gingival sulcus for the process offabricating the oral appliance.

While FIG. 6A depicts an augment extending completely around the toothand/or gum line of the patient, it should be understood that otheraugments extending only along the front or back of the teeth structures,or even along one side of one or more teeth or any portion(s) thereof(i.e., along less than a single tooth width, or only between two teeth)are contemplated in various embodiments herein.

In various embodiments, the materials potentially used for the augment450 could include those with moldable properties, such as the abovementioned periodontal dressing, or wax, and as noted, could be applieddirectly in the patient's mouth before impressions are taken, or couldbe applied to the dental cast prior to fabrication of the oralappliance.

Adding a periodontal dressing or other augment to at least a portion ofa patients dentition and/or to a dental cast proximate at the gingivalsulcus can create a “path” or channel proximate to the tooth/gumjunction that can serve several functions: (1) the path or channel canprovide a conduit within the oral appliance for the transfer and/orapplication of negative pressure to the gingival sulcus; (2) the path orchannel can make the oral appliance easier to apply and remove, withless chance for the appliance to become wedged in any concavities of thepatient's dentition; and/or (3) the path or channel can provide aconduit for the egress of tissue fluids, and if needed, gases, as theyfollow the negative pressure gradient, which could include wastemetabolites and/or microbial flora removed by suction force. If desired,at least a portion of the channel and/or some portion of the oralappliance could contact one or more tooth surfaces, gum surfaces, palatesurfaces, gingival surfaces, mucosal margin surfaces, the alveolarmucosa or even possibly the buccal mucosa. In various embodiments, theappliance can include one or more flexible and/or pliable surfaces oredges, which can desirably self-seal to adjacent anatomical structureswithout interfering with normal respiration of the patient through thenostrils and/or mouth. Desirably, through the combination of theflexibility of the appliance, and the ability to make an airtight and/orvacuum-tight seal (and/or partial seal thereof) at the areas where theappliance is in contact with some or all of the moist gingival surfacesand/or the tooth surfaces, the application of negative pressure to theconcave surface of the appliance will desirably allow the appliance tobe “compressed” or drawn towards the surface of the maxillary ormandibular dentition and/or gums (i.e., compressing the oral applianceusing negative pressure to subject the oral wound and the oral applianceto a first pressure which is low enough to provide therapy to the oralwound and high enough to maintain a seal between the oral appliance andat least one of the members of the group consisting of the patient'sdentition and a gum tissue of the patient), with the same mechanics asthose that keep a suction cup on a wall. Since the teeth can act as ascaffold to provide for even distribution of the negative pressure, withthis negative pressure distributed by the combination partly of thespaces between the teeth and partly due to the above mentioned channelthat would focus pressure on the gingival sulcus, the appliance wouldlikely not need any supplemental distribution devices, such as thesponge dressing that is required in wounds of the torso and theextremities. To illustrate with a simple example, if one thinks of atent, the oral appliance could be the fabric of the tent, and the teeth(and/or portions of the appliance that contact the teeth) could beanalogized as the tent poles. The space between the tent poles isanalogous to the spaces between the teeth. If a fan were blowing air outof the tent, as long as the tent poles are holding up the tent, the tentwill desirably not collapse under the reduced pressure. If desired, atleast a portion of the channel and/or the oral appliance could contactone or more of the lingual surfaces (i.e., contacting the tongue), thebuccal surfaces (i.e., contacting the inner aspect of the cheeks) and/orthe labial surfaces (i.e., contacting the inner aspect of the lips)outside of the dentition, as well as other surfaces within the mouth.

In one exemplary embodiment, such as shown in FIGS. 6B and 6C, adental/periodontal dressing or augment 600 (or other material intendedfor forming the channel, including the augments previously described)may be placed on or adjacent to a tooth and/or gum structure 610 priorto making an impression of the patient's teeth. Alternatively, thedental professional may place a dental/periodontal dressing at orproximate to the gingival sulcus base on a patient's dental mold (castmodel of the patient's teeth). Such periodontal dressings may includevarious types of materials, such as wax, clay or other commonly acceptedperiodontal dressings used in the industry (e.g., where the periodontaldressing composition may contain zinc oxide with eugenol, zinc oxidewithout eugenol, quaternary aluminum borate cement, cyanoacrylate,etc.). The periodontal dressings may be applied with a thickness and/orshape that desirably corresponds to a thickness and/or shape of theresulting channel, which in at least one exemplary embodiment comprisesa thickness of 2-5 mm at or proximate to the base of the gingivalsulcus, with a rounded or curved upper surface.

In other exemplary embodiments, a suitable oral appliance may befabricated by a service provider such as a periodontist or by thepatient's general dentist. A dental impression, which is a negativeimprint of some or all of the hard and/or soft tissues in the mouth, canbe utilized to make a positive impression, or dental cast. A series ofone or more channels could be sculpted into the negative imprint (i.e.,removal of impression material from the negative would desirably resultin an intentional “void” in the oral appliance, such as one or more“channels”), or additional material could be added to the cast (i.e.,addition of material to the dental cast would desirably result in anintentional “void” in the oral appliance). Impression materials could bedesigned to be a viscous liquid, a semi-solid, a solid material and/or athixotropic material. If desired, a combination of two or more differentimpression materials could be used, or the same impression materialhaving two different consistencies. Impression materials could be heldby a container (i.e., a tray) designed to roughly fit over the dentalarches, and quickly set to a solid (usually in a few minutes dependingon the material), leaving an imprint of the structures of the mouth. Ifdesired, a plurality of channels could be created, including two or moreparallel channels proximate to similar gum tissues/dentition and/or twoor more channels along different areas of the dentition within the sameoral appliance.

Where a dental impression is taken, it would desirably capture a part orall of a patient's dentition and some or all of the surroundingstructures of the oral cavity that are intended to be in contact withand/or adjacent to the negative pressure environment (see FIG. 7) and/orthe oral appliance—one exemplary embodiment of a suitable appliancecould include a palate contact surface, such as shown in FIG. 16. In oneexemplary embodiment, the dental impression may include at least one ormore surfaces within the oral cavity, including lingual, facial (i.e.,labial or buccal), proximal (mesial, distal), occlusal and/or incisalridge or edge (see FIG. 9). Various surrounding structures and/ortissues included in such an impression may further include at least oneof the hard palate, the soft palate, the floor of the mouth, the gingiva(i.e., from all or some portion of the surface of the teeth to themucosal margin) and/or the teeth.

In various alternative embodiments, the patient may choose to completean impression without professional dental assistance, with theimpression performed by using a “home impression kit.” The kit mayinclude some viscous, thixotropic (or other type) material that can beintroduced into the mouth via a stock dental impression tray (see FIGS.8A through 8D and FIG. 10), where the patient may take an impression oftheir own teeth, wait for the impression to solidify, and forward (i.e.,mail) the impression to a 3^(rd) party manufacturer to create the customsuction oral appliance (adding the additional material to the cast (see450 of FIG. 8C) to create a channel for application of negative pressure(see 710 of FIG. 8D). Stock impression trays can be manufactured invarious range of sizes and shapes, from which the closest size and/orshape tray can be selected that matches the dimensions of the dentalarches (or portions thereof) of the person who is to receive theimpression. Such stock trays may be manufactured from different types ofmaterials that are commonly used in the industry (i.e., metals,elastomeric materials such as polysulfides, silicones, or polyethersand/or Plaster of Paris). Alternatively, a periodontist, dentist orother dental professional may take an in-office impression of apatient's teeth using a special or custom tray. The custom or specialtray may be specialized to fit a specific patient's mouth, and may comeequipped with a handle and/or other manipulation features for easyremoval. The special or custom trays may be manufactured from anyaccepted materials commonly known in the industry, and is variousembodiments would include materials and/or features to allowperforations, apertures, channels or other features to be created bydrilling or other tools prior to the creation of the oral appliance.

In various additional embodiments, an oral appliance might be designed,manufactured and/or fitted to a patient utilizing non-invasive imagingdata, which could include Panorex data, CT-Scan data (including dentalcone beam CT scan), MRI scan data, X-ray data, ultrasound or sonogramdata, laser scanning and/or other minimally invasive and/or non-invasivedata. In other embodiments, visual depictions of the oral environment,including camera phone pictures (which might include sizing templatesheld within the field of view), might be uploaded to a website andutilized to create a 3D rendering of some or all of the oral cavity.Creation of the suitable oral appliance can include the computer aideddesign and/or manufacturing (including 3D printing or molding/machiningor oral appliances) of patient specific and/or patient adapted featureshaving various pre-defined shapes, sizes, widths, spans, thicknessesand/or contours based, at least partially, off of anatomical shapeinformation obtained from one or more pre-operative scans.

FIGS. 8A through 8C depict exemplary methods of creating an oralappliance from a patient's dentition and/or from a dental cast thereof.As noted above, an augment or dental/periodontal dressing has beenapplied to the gingival sulcus (and/or other anatomy) of a patient'sdentition or to a dental cast thereof (see also FIG. 6A, feature labeled450), a dental impression tray 700 containing a pliable impressionmaterial can be placed over the dentition/cast and an impression made ofthe region of interest (see region 450 in FIG. 8C). Once the materialwithin the impression tray 700 has hardened, the impression can beremoved, with the impression comprising a negative image of the area ofinterest (see FIG. 8D), which in various embodiments can desirablyinclude voids and/or channels 710 positioned proximate to the gingivalsulcus and/or other locations proximate the teeth and/or soft tissues(which could correspond to the location and/or size of the augment ordental/periodontal dressing previously noted).

Desirably, the dental impression will result in an imprint (i.e., a‘negative’ mold) of teeth and soft tissues, which can then be used tomake a cast of the dentition. A cast of the dentition is athree-dimensional “positive” model of the patient's dentition (i.e., apatient's maxillary and mandibular arches), which may allow a dentist todetermine the optimal locations for application of negative pressuretreatment, treatment planning, patient education and development of thedesired contact surface(s) required for treating the affected areasinvolved with periodontal pocket formation (see FIGS. 4A through 4E). Invarious embodiments, various features such as apertures, channels,sealing features and/or related shapes could be created by modifying thedental cast, by modifying the shape of patient's dentition, and/or bymodifying the shape of the ultimate cast, formed or molded appliance.Such techniques could include applying a periodontal dressing to theregion of the gingival sulcus on the dental cast prior to the creationof the oral appliance, and/or machining of the appliance to removematerial in a desired manner (including the creation of channels and/oropenings as described herein, or various combinations thereof). Variousmaterials, methods and techniques known in the art may be used to createan appropriate anatomic model of the oral appliance, which can becustomized as necessary for each patient's required treatment. Forexample, gypsum or plaster may be used to construct a cast, and similarmaterials having some degree of moldability (i.e., wax) could be used tomodify the cast to direct, apply and/or concentrate negative pressure ina desired and/or appropriate manner.

In various embodiments, an oral appliance can desirably be fashionedfrom the impression tray 700 (FIG. 8D), with the associated channels710. As best seen in FIGS. 11A through 11D, an oral appliance 800 foruse with the present invention can include inner surfaces that abut thepatient's teeth and gums that are configured to substantially match atleast some portion of the patient's dentition, with at least one channel720 (see FIG. 11D) proximate to the gingival sulcus.

Desirably, a source of negative pressure (i.e., a vacuum source) can beprovided to the oral appliance, with the negative pressure transferredto the channel 710 for application to the patient's anatomy. In at leastone exemplary embodiment, an oral appliance 800 (see FIG. 12) caninclude an attachment point 810 for one or more tubes (includingmultiple tubes, not shown), with the attachment point 810 including alumen 820 which can connect to channel 710 on the inner surface of theappliance 800. Desirably, the attachment point 810 will be positioned ona frontal surface of the oral appliance 800, and would most desirablyextend comfortably between the lips of the wearer when the appliance wasin a desired position. If desired, the attachment point could includeflattened outer surfaces to more comfortably fit between/against thelips of the wearer, although various other positions and mountingarrangements for the attachment point are contemplated herein. Moreover,alternative embodiments could incorporate the use of multiple tubes andattachment points, including multiple vacuum lines and/or a combinationof supply and vacuum lines for the sequential and/or intermittentapplication of medicaments and vacuum, etc.

FIGS. 15A and 15B depict one embodiment of an oral appliance with a dualtubing arrangement that could be utilized by one exemplary method forretaining an oral appliance on a desired location of the patient'sdentition during intermittent negative pressure therapy. In thisembodiment, a first channel can be provided that applies a first amountof negative pressure P_(A) to a first region A of the dentition, and asecond channel can be provided that applies a second amount of negativepressure P_(B) to a second region B of the dentition. If desired, thefirst and second negative pressures could be applied in an alternatingfashion, with at least some portion of the oral appliance being“compressed” and/or drawn towards the relevant portion of the dentitionat all times.

The oral appliance may be comprised of commonly available materialscurrently used in dental applications and also in the production ofsport mouth guards (i.e., a semi-flexible plastic such as Ethylene VinylCopolymer, commercially available from Henry Schein, Inc. of Melville,N.Y., USA) which can be processed and shaped using standard vacuumforming processes known in the industry. If desired, vacuum formingtechniques can facilitate modification of the shape of the oralappliance to accommodate a variety of attachment point types and/ordesigns for the suction and/or supply tubing. This suction tube may befixed or may include a removable connection, and one of more tubes couldbe utilized for application of negative pressure and/or removal oftissue exudate.

If desired, one or more attachment points or adapters for the tubingmight, to some degree, contact the front teeth and/or side teethproximate to the mouth, with the lumen of the tubing desirablydelivering negative pressure to the channel created along the gingivalsulcus (which could include direct contact with the lumen and/orindirect contact with a lumen via the spaces between the teeth and/orvia a lumen surrounding the back teeth of the appliance).

In various embodiments, negative pressure can be distributed to thegingival sulcus, which is the margin between the tooth and gum tissuebut the channels could have different shapes and/or configurations, suchas the various shapes illustrated in the schematic cross-sections ofFIGS. 13A through 13F.

In various embodiments, an oral appliance could include patient adaptedand/or patient specific features that correspond to some or all of apatient's upper dentition (and/or related soft tissues) and/or lowerdentition (and/or related soft tissues). If desired, an upper dentitioncomponent and/or lower dentition component could comprise a non-clearpolymeric or elastomeric material, such as a translucent blue or opaquetooth color, for example. The clear or opaque polymeric material mayhave additional properties, such as improved resistance to stainingand/or color leaching. In addition, the polymer may not exhibit any odoror taste, yet still be substantially flexible and contain proper tensileand impact properties. The polymeric material may also be made clear oropaque.

In various embodiments, the oral appliance may be fashioned to focus adesired amount of negative pressure on a specific area of the patient'sanatomy, which could include application to a partial upper dentitionand/or a partial lower dentition (i.e., only a lateral or medial side ofa tooth section and/or a portion of multiple teeth and/or a singletooth). In other embodiments, one or more channels in the oral appliancecould be sized and/or arranged to apply a desired amount of negativepressure on a specific portion of the patient's gingiva and/or alveolarmucosa or to a region on the patient's palate. In various embodiments,the channels and oral appliance components could maintain sufficientstructural integrity such that the channels desirably do not collapse(or do not collapse a significant amount) upon application of negativepressure, while in other embodiments a partial and/or complete collapseof the channels may be desired.

For example, in the embodiment of FIG. 13A, the channel 710A isdesirably sized and arranged to apply negative pressure to a deep pocketarea 320A of the patient's dentition, with a significant upper portion805A of the appliance directly compressed against and contacting thetooth 260A. However, this negative pressure may also draw a lowersurface portion 810A of the oral appliance 800A towards and into contactwith a portion of the free gingiva 185A, which may push the free gingiva185A into contact with the tooth 260A, potentially squeezing the freegingiva 185A between the appliance 800A and the tooth 260A potentiallyclosing and blocking egress of tissue fluid from the deep pocket area320A.

While pocket closure might be desirable in some situations, alternativechannel designs may avoid the potential pocket closure as the negativepressure “compresses” the appliance and brings the surface of theappliance in contact with the gingival surfaces. For example, FIG. 13Bdepicts a channel 710B that is desirably sized and arranged to applynegative pressure to a deep pocket area 320B of the patient's dentition,wherein a lower surface portion 810B of the oral appliance 800B contactsthe gingiva 185B below the deepest portion of the deep pocket area 320B,on the attached gingiva.

FIGS. 13C through 13F depict additional exemplary embodiments ofchannels of differing shape, size and/or design, including portions ofthe oral appliances (800C in FIG. 13C; 800D in FIG. 13D; 800E in FIG.13E and 800F in FIG. 13F, respectively) that compress against and/orcontact various surfaces of the patient's anatomy.

In various embodiments, an oral appliance can be fabricated to includeone or more surfaces that directly contact and/or compress againstvarious portions of the attached gingiva, as illustrated in FIG. 4B asCS (center section) of the patient's dentition. This attached gingiva islocated somewhat distal from the teeth, and appliance contact with thissurface desirably allows the appliance to contact gingival tissuesbeyond the gingival sulcus. By fabricating this appliance from thedental cast which near perfectly reflects the patient's individualanatomic morphology (in this exemplary embodiment), the appliancedesirably conforms precisely to various hard and/or soft tissues of thepatient's anatomy. The contact area is also illustrated by structure 180in either FIG. 4C or 4E, allowing for appliance contact with healthiertissues and/or tissues having relatively more structural integrity thantissues affected by the periodontal pocket formation.

In yet another embodiment, an oral appliance could include an upperdentition component configured to be received on a patient's upper(maxillary) teeth, and formed to substantially conform to the contoursof the patient's upper teeth, and upper dental arch, including therear-most molars and some of the hard palate, such as the appliancedepicted in FIG. 16. An exemplary upper dentition component may includean upper edge, a center section and a lower section, such as illustratedin FIG. 4B. The upper edge that may be configured as the edge thatreaches a mucosal margin or the mucogingival junction of the patient(see 190 of FIG. 4B) which separates the attached gingiva 180 from thealveolar mucosa 205. The edge of the appliance, to accommodate thisanatomical aspect, may include a wavy, scalloped shape/configuration(not shown) to desirably replicate a patient's mucogingival junction. Inother embodiments, an oral appliance could include an upper dentitioncomponent configured to be received on a patient's upper (maxillary)teeth, and formed to substantially conform to the contours of thepatient's upper teeth, and upper dental arch, including the rear-mostmolars. In certain embodiments, the upper edge could be configured suchthat the edge might reach and/or overlap at least a portion of apatient's attached gingiva.

In various embodiments, an oral appliance could include an upperdentition component, with one or more surfaces of the appliancedesirably that could be in contact with an attached gingiva on surfacesadjacent to the cheeks (buccal) and lips (labial). This embodiment of anappliance could cover all of the dentition, if desired, and for the morecentral (lingual) area of gingival contact, sufficient contact area onthe lingual gingiva tissue could seal the surface under the appliancecompression to a sufficient degree to facilitate the transfer ofnegative pressure to a targeted anatomical region without displacementof the oral appliance and/or causing patient discomfort. Alternatively,an oral appliance may incorporate one or more surfaces in contact withthe hard palate of a patient, which could provide sufficient appliancecompression contact with the patient's tissues to seal the area underthe appliance to a sufficient degree to facilitate the transfer ofnegative pressure to a targeted anatomical region without significantdisplacement of the oral appliance and/or causing patient discomfort.Additionally, contact of the appliance with the palate, which can beseen in the prototype orthosis of FIG. 16, could be advantageous invarious embodiments since some of the strongest movements of the tongueare in apposition to the palate, and by allowing appliance contact withthe palate, there is a decreased chance of involuntary tongue movementsdisplacing the appliance and disrupting the seal (to maintain thesuction/negative pressure). In various embodiments, the tongue may be incontact with lingual aspects of an oral appliance, which in variousother embodiments could provide additional surface area for tissuecontact. Where the compressed oral appliance can provide sufficientcontact with various regions of the patient's anatomy (which may includethe use of flexible and/or pliable materials in the oral appliance tocontact such anatomy), there may be no need for supplemental sealingmaterials such as dental adhesives to create a sufficient seal. Ifdesired, there may be variations in the materials used in parts of theoral appliance in contact with the arch, the dentition or the gingivalsulcus region, possibly comprising a variety of different materialshaving differing properties (i.e., tensile strength, compression,flexibility, clarity, etc.), including the use of multiple materials ofdiffering strength, compression and/or flexibility characteristics,including the use of a flexible ridge or tab of material to effect adesired seal at the periphery of the appliance, the gums and/or thedentition.

In various embodiments, an oral appliance may include a lower dentitioncomponent, which could be configured to be received on a patient's lower(mandibular) teeth, and this component could be formed to substantiallyconform to various contours of patient's lower teeth and/or the interiorof the entire lower dental arch (floor of mouth), including behind therearmost molars. The lower dentition component may substantially conformto the patient's anatomy. In a preferred embodiment, the appliance mayalso extend into and/or beyond the attached gingiva, since this regionof tissue could desirably have more structural integrity than variousother tissues affected by the periodontal pocket formation, as well asto create the suction seal, and also would desirably not be moved orloosened by random movements of the tongue.

Similar to the upper dentition component previously described, an oralappliance comprising a lower dentition component could include one ormore surfaces to contact and compress against the dentition LS (FIG. 4B)of the patient and the attached gingiva CS. If desired, the margin ofthe appliance could be modified to reflect the wavy, scallopedconfiguration of the patients mucogingival junction 190 to replicatethis aspect of the patient's anatomy. The appliance in certainembodiments could have contact with either attached gingiva 180 oralveolar mucosa 205 at the lower edge. Similar to the upper dentitionappliance, the lower dentition component could also be fabricated with achannel created by applying a periodontal dressing to the gingivalsulcus on the dental cast to create an oral appliance that focuses thenegative pressure on the gingival sulcus. If desired, the outermost edgeof the appliance may comprise a flexible material to promote thegingival contact necessary to compress the appliance and maintain thenegative pressure environment between the appliance and the underlyingtissues during vacuum application.

In various embodiments, an oral appliance comprising a lower dentitioncomponent could similarly cover all of the patient's lower dentition,including posterior to the back molars, with contact on gingivalsurfaces, which could allow the appliance to exploit the naturalmoisture of the gingival surfaces to create a seal for transfer of thenegative pressure environment to the deep pockets. The lower dentitioncomponent may include one or more surfaces that contact an attachedgingiva. The lower dental arch portion may extend as deep as possible,desirably without impinging on the soft tissues to avoid causing patientdiscomfort. As similarly described above for the upper component, theappliance may be comprised of materials with different properties,(i.e., tensile strength, compression, flexibility, clarity, etc.).

In various embodiments, an oral appliance can be fabricated to includeone or more surfaces that directly contact various portions of the“center section” CS of the patient's dentition (see FIG. 4B), which areareas located somewhat distal from the teeth (wherein the appliancecontacts additional gum tissues beyond the gingival sulcus). Thisappliance would desirably substantially conform to various hard and/orsoft tissues of the patient's anatomy, and in a preferred embodiment theappliance could extend up to and/or beyond the “attached gingiva” (whichcould include contact with healthier tissues and/or tissues havingrelatively more structural integrity than tissues affected by theperiodontal pocket formation.

While pocket closure might be desirable in some situations, otherarrangements and/or alternative channel designs may provide for variousother desired treatments of the patient's condition. For example, achannel could be desirably sized and/or arranged to apply negativepressure to a deep pocket area of the patient's dentition, wherein alower surface portion of the oral appliance compresses against and/orcontacts the gingiva at or near the deepest portion of the deep pocketarea. Other embodiments could include a channel that is desirably sizedand arranged to apply negative pressure to a deep pocket area of thepatient's dentition, wherein a lower surface portion of the oralappliance is compressed against and/or contacts the gingiva at alocation below the deepest portion of the deep pocket area. Still otherembodiments could incorporate a channel that is desirably sized andarranged to apply negative pressure to a deep pocket area of thepatient's dentition, wherein a lower surface portion of the oralappliance is compressed against and/or contacts the alveolar mucosa at alocation that may be at or below a root of the tooth. If desired, achannel of varying sizes, shapes and/or locations could be created, withsome or all of the channel wall(s) following, mimicking or approximatingthe individual depth of pockets proximate to each tooth.

In various embodiments, an oral appliance could include various featuresthat (1) assist with equal and/or controlled distribution of negativepressure to targeted anatomical areas, (2) may provide a pathway andgradient for removal of tissue exudate, and (3) allow for ease ofapplication and removal of the appliance. The oral appliance mayoptionally include one or more surfaces in contact with the tongue(lingual) and/or surfaces that contact the inner aspect of the cheeks(buccal) and lips (labial).

A wide variety of path or channel features can be provided on an oralappliance, including a plurality of channels that may or may notcommunicate with each other. Channel features may extend along thepatient's entire upper and/or lower dentition, or along various portionsthereof. If desired, at least a portion of the lingual, labial and/orbuccal surfaces of the upper and/or lower dentition may include at leasta portion of a path or channel (not shown) that may extend from occlusalto incisal to occlusal teeth, including along the complete perimeter ofthe teeth. Alternatively, the path or channel may be focused on aspecific region or diseased area, where the path or channel may extendalong only a portion of the teeth from the incisal to occlusal teeth. Inaddition, the width, depth and/or other shape features of the channelmay alter along a portion of the teeth, which could include wider orshallower channel regions proximate to more diseased regions, andthinner channels proximate to more healthy tissues.

In one exemplary embodiment, a recessed path or channel could desirablybe located at the level of the gingival sulcus and/or the free gingivalgroove of a healthy patient's gingiva. The diameter or width of the pathor channel may be configured to extend proximate to the gingival marginand proximate to the free gingival groove of both upper and/or lowerdentition components. This diameter or width may be approximately 1-5 mmfor a healthy patient, or the dimensions of the channel for treatment ofmore diseased patients might have one component parallel (channel width)and one component perpendicular to the gum tissue (channel depth), witheither dimension in the range of 1 to 5 mm (or more). A channel mayinclude various configurations (i.e., rounded, squared, triangular,hemispherical, fusiform, elliptical, etc.). In addition, theconfiguration of a channel may be manufactured by removing material fromthe wall thickness of the oral appliance, or the channel dimensions mayextend outwardly (i.e., bulge outward) while maintaining a consistentwall thickness.

As best seen in FIGS. 11A, 11B and FIG. 12, an attachment point oraperture 810 (FIG. 12) can be provided on the oral appliance, with thedisclosed aperture desirably positioned midline of the patient's mouthfor comfort. In other embodiments, the aperture may be positionedanywhere along a front surface (i.e., the anterior aspect) of theappliance. The aperture may be sized and configured to fit within therecessed channel or path of the appliance, and the aperture could beslightly to the right or left depending on patient anatomy or patientpreference, but its location would most desirably be limited by themargins of the lips (although other attachment points distal from themouth are contemplated herein). Alternatively, a raised surface,additional cavity and/or additional space can be created at front of theupper and/or lower dentition component, including designs thatfacilitate the attachment of the negative pressure suction tubing to theappliance in a manner to reduce and/or eliminate the opportunity forbending stresses on the teeth, for eliminating inadvertent causation ofpatient discomfort, and/or for preventing possible tooth fracture ifexcessive bending forces were applied.

If desired, various embodiments could incorporate an antibiotic gel orsimilar medicament, which could be impregnated into the oral appliance.For example, if an antibiotic gel was delivered through the channel to adiseased anatomy (i.e., during a “pressurized” phase where gel is“pushed” into the appliance and/or during a “relaxation” phase wherepressure is increased proximate to atmospheric pressures), theantibiotic gel may enter the periodontal pocket, and possibly migrate toa bottom of the pocket. Such motion of the gel might be furtherfacilitated by intermittent “pulsing” of vacuum and pressure, whichcould help flush out unwanted fluids and/or materials while concurrentlydelivering a medicament treatment. If desired, the antibiotic gelcomposition might be of a sufficiently thick consistency such that itwould not easily be extruded by the elasticity of the gingival tissue,and not washed away by saliva, nor extruded by the mechanical forcesapplied to the gums by normal mouth movements and eating/chewing. Asidefrom potential delivery of an antibiotic gel, since the appliance woulddesirably be in close apposition to the teeth and gingival tissue, theappliance could also concentrate other locally appliedmedications/treatments to these tissues, including whitening agents forthe teeth, fluoride, and/or other medications as indicated. Thesemedications/treatments could be formulated to have adequate viscosity sothat they were not sucked into the lumen, but remained adjacent to thetissues being treated, kept in place by the negative pressureenvironment securing the appliance. In various embodiments, a medicamentmay be applied to the dentition and/or gums during a low pressure orappliance “compression” phase, which may then potentially be drawn intothe periodontal pocket by the natural relaxation of tissues during ahigher pressure or appliance “decompression” phase (i.e., when pressurein the appliance is increased and/or released to the surroundingatmospheric pressure and the tissues “rebound”).

In various embodiments, a tubular adapter or other attachment could beconnected to the aperture, which could be connected to a source ofnegative pressure. The tubular adapter could be virtually anycommercially available adapter, or it may be a custom fashioned adapterconfigured as a transition to a multi-lumen tube system. In anotherembodiment, a multi-lumen tube system may include an oral appliance tubeconnection/aperture, a multi-lumen tube, a transition tube, transitionadaptor, a tube clip, and/or a negative pressure tube adapter.

As best seen in FIG. 14, a multi-lumen tube 900 (or suction tube)connected to the oral appliance may include one or more lumens 910 forextracting tissue fluid/tissue exudate, along with auxiliary channels920 for measuring pressure (i.e., a pressure transducer), in a mannersimilar to pressure monitoring features currently incorporated into theWound VAC system offered by Acelity/KCl. In various alternativeembodiments, however, the need to incorporate a pressure transducercapability in the orthosis and/or other system components may be lesscompelling. Since the mouth is typically very sensitive, the patientcould potentially tell if there were a significant loss of suction, asthe appliance would desirably feel loose and would potentially displace.If desired, the upper limit of applied negative pressure could becontrolled by the unit applying the negative pressure, or directly bythe user, or might include a pressure relief valve somewhere in theappliance, the tubing and/or the vacuum pump.

Unlike standard negative pressure therapies employed in the extremitiesand/or torso (which often require constant pressure assessment and/ormonitoring because blood in the lumen can clot (potentially reducingand/or negating the effects of treatment), such constant monitoring maynot be necessary in an oral application because the fluid passingthrough the tubing in the current proposed invention may only comprisesaliva and/other materials which do not clot (or which do not “clot” orotherwise harden to a significant level). If there were some obstructionof the tubing, as noted herein, the negative pressure from the vacuumsource would likely reduce and/or disappear within the channel(s) of theoral appliance, causing the appliance to “decompress” some varyingdegree and/or become easily dislodged and/or malpositioned. However, ifthis appliance were used to help augment healing in a traumatic injurywith potential bloody drainage, pressure monitoring could be animportant optional additional feature. With regard to the configurationof the tubing, it may be cylindrical or may be a flat, multi-lumen tube(not shown).

In one exemplary embodiment, a diameter of one exemplary multi-lumentube could be 7 mm or less, or optimally might be a custom size to fit apatient's mouth. The weight of the tube, the forces delivered by thelever arm/bending forces on the tube adapter, and/or the size and shapeof a patient's mouth should be considerations for the size andconfiguration of the method of attachment of the tube to the appliance.The dentist may have various sizes and configurations available toprovide a specialized fitting.

In addition, the single (optimal) or multi-lumen tube may be flexible,but desirably rigid enough to withstand continuous or intermittentnegative pressures in the ranges of 25-250 mmHg without significantcollapse. Intermittent negative pressure can include compressing theoral appliance using negative pressure to subject the oral wound and theoral appliance to a first pressure which is low enough to providetherapy to the oral wound and high enough to maintain a seal between theoral appliance and at least one of the members of the group consistingof the patient's dentition and a gum tissue of the patient, anddecompressing the oral appliance to a second pressure above the firstpressure sufficient to maintain the oral appliance in a desired positionon the patient's dentition while relaxing compression about the oralwound. Furthermore, since patient comfort may be paramount (i.e.,patients typically fail to comply with treatments that are nottolerable), designs that allow the patient to tolerate wearing the oralappliance for several hours at a time, usually overnight while sleeping,are desirous.

The oral appliance may include a tube adapter that could transition froma single to multi-lumen tube to allow for both the extraction of fluids,supply of medicaments and/or, if desired, monitoring of pressure.Commercially available single lumen drain tubes which are able to resistsuction forces are soft and flexible, as small as 6-7 mm in diameter,and are tolerable to be exiting the mouth without irritating the lips.If desired, a transition tube may be utilized (not shown) that comprisesa different size, configuration and/or function tube than the single ormulti-lumen tube (i.e., one of the functions of the transition tube maybe to connect to the negative pressure machine). The transition adaptormay be a component that facilitates the transition between the single ormulti-lumen tube to the transition tube.

In other embodiments, oral appliances can be constructed that desirablydirect a therapeutic vacuum or negative pressure to an oral wound site,such as an anatomical location where an oral surgical procedure hasoccurred. In such cases, the oral appliance may be particularized foruse at the wound site, which may include the creation of channels orcavities proximate to the surgical location. If desired, the oralappliance may include features to accommodate the surgical removal oftissues (i.e., subsequent to wisdom tooth removal and/or root canalprocedures), the surgical addition of tissues (i.e., to accommodate abone implant or tissue graft), or may be modified in some manner(including as described herein) to accommodate inflamed and/or swollentissues. In a similar manner, negative pressure oral systems, devicesand methods could have significant utility in the treatment of oralwounds resulting from injuries. If desired, the oral appliancesdescribed herein may be utilized to prepare an area for surgery (i.e.,to reduce inflammation and/or control infection in tissues targeted forsurgery and/or adjacent to intended surgical sites) as well as to treatand/or manage surgical sites after surgical procedures. In variousembodiments, such devices may be utilized in treating surgical anchorimplant sites and/or grafting sites, where healing of the site isdesirous prior to final implantation of a surgical implant and/or graft,as well as after the surgical procedure to promote healing of affectedtissues.

Given that bruxism, or involuntary clenching of the teeth, is a riskfactor for stress and potential damage to the periodontal ligaments dueto high occlusal pressures (i.e., including causing or contributing tocellular hypoxia), the presence of the oral appliance could in variousadditional embodiments add an element of intraoral neuromuscularfeedback, which could favorably decrease this involuntary clenching.

In various embodiments, a negative pressure vacuum machine may beprovided that is equipped with one or more custom features particular tothe present invention, or the system may simply incorporate use of acommercially available negative pressure/vacuum machine and/orattachment to an installed (I.e., permanent or semi-permanent) vacuumsource. For example, a portable suction machine can be used with variousembodiments of the present invention (i.e., many hospitals carry a widevariety of vacuum devices—from various manufacturers). A suitableportable suction machine may include minimal controls, such asdelivering a negative pressure range of 25-250 mmHg, have continuous andintermittent operation cycles, may be rechargeable, and may be of lowweight (i.e., approx. 5 lbs. or less, as opposed to the hospital basedsuction units that weigh upwards of 25 lbs.). Alternatively, a customnegative pressure/vacuum machine may be provided having more convenientfeatures such as portability (i.e., including ultra-light weightcomponents), battery power or rechargeable batteries, with design forsingle use, operator comfort, and be lightweight with ergonomicfeatures. One exemplary pressure could be between 25 and 50 mmHg, whichcould be continuous or intermittent.

What has been described above are examples of the present invention. Itis, of course, not possible to describe every conceivable combination ofcomponents or methodologies for purposes of describing the presentinvention, but one of ordinary skill in the art will recognize that manyfurther combinations and permutations of the present invention arepossible. Accordingly, the present invention is intended to embrace allsuch alterations, modifications and variations that fall within thespirit and scope of the appended claims. Although the foregoinginvention has been described in some detail by way of illustration andexample for purposes of clarity of understanding, it will be readilyapparent to those of ordinary skill in the art in light of the teachingsof this invention that certain changes and modifications may be madethereto without departing from the spirit or scope of the disclosureherein.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The foregoingembodiments are therefore to be considered in all respects illustrativerather than limiting on the invention described herein. Scope of theinvention is thus intended to include all changes that come within themeaning and range of equivalency of the descriptions provided herein.

The various headings and titles used herein are for the convenience ofthe reader, and should not be construed to limit or constrain any of thefeatures or disclosures thereunder to a specific embodiment orembodiments. It should be understood that various exemplary embodimentscould incorporate numerous combinations of the various advantages and/orfeatures described, with all manner of combinations of the variouselements which are contemplated and expressly incorporated hereunder.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention are to be construed to cover boththe singular and the plural, unless otherwise indicated herein orclearly contradicted by context. The terms “having,” “including,” and“containing” are to be construed as open-ended terms (i.e., meaning“including, but not limited to,”) unless otherwise noted. Recitation ofranges of values herein are merely intended to serve as a shorthandmethod of referring individually to each separate value falling withinthe range, unless otherwise indicated herein, and each separate value isincorporated into the specification as if it were individually recitedherein. All methods described herein can be performed in any suitableorder unless otherwise indicated herein or otherwise clearlycontradicted by context. The use of any and all examples, or exemplarylanguage (e.g., i.e., “such as”) provided herein, is intended merely tobetter illuminate the invention and does not pose a limitation on thescope of the invention unless otherwise claimed. No language in thespecification should be construed as indicating any non-claimed elementas essential to the practice of the invention.

What is claimed is:
 1. An oral appliance for attachment to a negativepressure source, comprising: an elongated orthosis which allows normalrespiration of a patient through a mouth of the patient without aid ofan external device, the elongated orthosis having a generally U-shapedcross-section with an anterior region, an intermediate region and alingual region, the anterior region having a first surface portion, thefirst surface portion substantially matching at least a portion of ananterior surface of a patient's dentition, the lingual region having asecond surface portion that substantially matches at least a portion ofa lingual surface of the patient's dentition, the anterior and lingualregions separated by the intermediate region; a first passage formedthrough at least a portion of the anterior region, a proximal end of thefirst passage in fluid communication with the negative pressure source;and a channel formed in the first surface portion of the anteriorregion, the channel located proximate to a gingival margin of thepatient's dentition during use, the channel in fluid communication witha distal end of the first passage.
 2. The oral appliance of claim 1,wherein the intermediate region includes an intermediate surfaceportion, the intermediate surface portion substantially matching atleast a portion of an incisal surface of at least one tooth of thepatient's dentition.
 3. The oral appliance of claim 1, wherein theintermediate region includes an intermediate surface portion, theintermediate surface portion substantially matching at least a portionof an occlusal surface of at least one tooth of the patient's dentition.4. The oral appliance of claim 1, wherein the anterior region furtherincludes a third surface portion, the third surface portionsubstantially matching at least a portion of a gum tissue proximate tothe patient's dentition, the channel being located between the firstsurface portion and the third surface portion.
 5. The oral appliance ofclaim 4, wherein the first and second surface portions comprise aflexible material.
 6. The oral appliance of claim 1, wherein the lingualregion includes a second channel formed in the second surface portion,the second channel located proximate to a second gingival margin of thepatient's dentition.
 7. An oral appliance for attachment to a negativepressure source, comprising: a curved orthosis having a generallyC-shaped cross-section with a first region, and a second region and athird region, the first region having a first contact surface, a portionof the first contact surface substantially matching at least a portionof a first tooth surface of a patient, the second region having a secondcontact surface, a portion of the second contact surface substantiallymatching at least a portion of a second tooth surface of the patient,the first and second regions separated by the third region; a firstpassage extending through the first region, a first end of the firstpassage in fluid communication with the negative pressure source; and achannel formed in the first region, the channel positioned over alocation adjacent to a position of a gingival sulcus of the tooth of thepatient, at least a portion of the channel in fluid communication withthe first passage, the first region including a flexible surface whichprovides a fluid seal against a tissue surface of the patient to sealthe channel and retain a negative pressure from the negative pressuresource in local proximity to the gingival sulcus.
 8. The oral applianceof claim 7, wherein the portion of the first contact surfacesubstantially matches a facial surface portion of at least one tooth ofthe patient's dentition.
 9. The oral appliance of claim 8, wherein theportion of the second contact surface substantially matches a lingualsurface portion of the at least one tooth of the patient's dentition.10. The oral appliance of claim 7, wherein the second region furtherincludes a gum contact surface, at least a portion of the gum contactsurface substantially matching and engaging with at least a portion of agum tissue proximate to the first surface of the tooth.
 11. The oralappliance of claim 10, wherein the first region spans a plurality ofteeth of the patient.
 12. The oral appliance of claim 10, wherein thechannel spans a plurality of teeth of the patient.
 13. The oralappliance of claim 7, wherein the third region includes a third contactsurface, at least a portion of the third contact surface substantiallymatching at least an occlusal portion of a tooth of the patient.
 14. Anoral appliance for attachment to a negative pressure source, comprising:an elongated orthosis which does not substantially interfere withrespiration of a patient through a mouth of the patient, the elongatedorthosis having a generally U-shaped cross-section with an anteriorregion, an intermediate region and a lingual region, the anterior regionhaving a first surface portion, the first surface portion substantiallymatching at least a portion of an anterior surface of a patient'sdentition, the lingual region having a second surface portion thatsubstantially matches at least a portion of a lingual surface of thepatient's dentition, the anterior and lingual regions separated by theintermediate region; a first passage formed through at least a portionof the anterior region, a proximal end of the first passage in fluidcommunication with the negative pressure source; and a channel formed inat least one of the first and second surface portions, the channelpositioned over a location matching a position of a gingival sulcus ofthe patient's dentition, the channel in fluid communication with adistal end of the first passage, at least one of the anterior andlingual regions including at least one flexible surface which provides afluid seal against a tissue surface of the patient to seal the channeland retain a negative pressure from the negative pressure source inlocal proximity to the gingival sulcus.
 15. The oral appliance of claim14, wherein the anterior region spans a plurality of teeth of thepatient.
 16. The oral appliance of claim 14, wherein the channel spans aplurality of teeth of the patient.
 17. The oral appliance of claim 14,wherein the intermediate region includes a third surface portion thatsubstantially matches at least a portion of an occlusal surface of thepatient's dentition.
 18. The oral appliance of claim 14, wherein theanterior, lingual and intermediate regions each comprise a flexiblematerial.
 19. The oral appliance of claim 14, wherein the anterior andlingual surfaces of the patient's dentition are on a single tooth. 20.The oral appliance of claim 14, wherein the elongated orthosisencompasses an entire dental arch of the patient.